Dust-proof mechanism for a positioning cover



FIG. 1 is a perspective view of a dust-proof mechanism for a positioning cover showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is another perspective view thereof; and,

FIG. 9 is an assembled view for showing the dust-proof mechanism for a positioning cover which is assembled between a pushing car and a wheel, wherein the broken line portion is for illustrative purpose only and forms no part of the claimed design. 

CLAIM The ornamental design for a dust-proof mechanism for a positioning cover, as shown and described. 